Hello,

After Arming the board, when trying to take off, the vehicle flipped off instantly. Never it went to hovering mode. After giving 15 % throttle, quad flipped .

This is my configuration.

1. DYS 20Amp ESC

2. KK 2.1 FLight controller with LCD

3. DYS motors with 1000KV, 150W

4. HK Transmitter & Rx, T6A V2 :
http://www.hobbyking.com/hobbyking/s...2_mode_2_.html

5. Nano Tech Lipo 4s, 4500maH, 35C.

6. Props 8x4.5

7. "+" Configuration selected from FC board.

I have checked motor connection, rotation direction, prop direction. It appears to be fine. What could be the reason for it

you need to check trims of yaw, roll and pitch on your kk board. callibrate your pots.

make sure u have right mode selected in kk2, x or + ,
caliberate the sensors/accelerometers in kk2 on a flat surface and caliberate throttle in escs.
and make sure transmitter is set properly and channels connected correctly.
go to receiver test in kk2 and make sure all signals are correct.

Thank you Guys, I will check and update you . Once again thank you for your prompt reply